---- Installation Instruction ----

Chap 2 _How to adjust focusing screen

The Focusing Screen has already made the best thickness concert camera.You can also test by yourself

There are a few methods making reference to (Adjust screen to only influence is MF accuracy , AF focus and focusing screen is extraneous!!)


A. Principle Explain

<P1>Focusing screen relationship with camera

The <P1> is the path relation between focusing screen and camera ccd/cmos and AF sensor, Normal camera light path should be L1 = L2 = L3,
If L1 L2 focus manually will not be accurate,If L2 L3 Auto focus will not be accurate,Some frequent AF front or back focus cameras may be this reason.


B. Test Focusing Screen

<Method 1 >Using AF lens to test focus---Employ path L3 to adjust path L1(Fit for split-image screens)

If the focus of your AF lens is accurate,You can use this method.Press the shutter button halfway to focus and see the image of viewfinder window......

<P2>The focusing screen in the dissimilarity focal image


<Method 2 >Using MF lens/Mode to test focus---Employ path L2 to adjust path L1(This method is the most accurate, Fit for split-image and micro-prism screens)

Set the lens focus mode switch to mf and focus manually,Back focus= L1> L2, Front focus= L1<L2


<P3>Prepare a ruler,The target is scale of "7"


<P4> This is lost focus image.


<P5>The focus is scale of "7"


<P6>This is central image enlarges,After focusing completion please take photo


<P7>If the photo focus is scale of "7" ,that focus is exactitude

If the photo focus is scale of "7" denotes L1 = L2 (The focusing screen path equal CCD/CMOS path )

The work has already ended ^^


<P8>If the photo focus is scale of "6" that is back focus,About adjust back focus please refer to this


<P9>If the photo focus is scale of "8" that is front focus,About adjust front focus please refer to this


C. Focusing Screen Adjust

<Back focus amendment>

Please checking the all spare parts and confirmation Install it

If check it all right and still back focus,You can use "transparent pad flake"

The back focus meanings be L1>L2,Reduce L1 distance can revise,You can use Transparent pad to revise<P10>.

Putting Transparent pad first then putting focusing screen can reduce the distance L1<P11>.


<P10> Transparent pad: It's used to adjust back focus


<P11>The position that the transparent pad puts


<Front focus amendment>

This possibility is low,You can check....

1.Whether focusing screen and other spare parts put orderliness or no??

2.The spare parts buckled??

3.The metal flake didn't put like or distortion??

If check it all right and still front focus,You can take out the metals correction slice in the camera away can revise front focus


<The front focus is a lot of ??>

Only have a reason .....is......The focusing screen puts contrary!!